Biodiesel induced corrosion and degradation: Review

Rapid depletion of fossil fuel resources as well as concerns for foreign dependence in meeting energy needs have led researches for alternative fuels. Biodiesel, which can be obtained from many renewable resources such as vegetable oil and animal fat through transesterification, is the most attractive alternative fuel for cars, especially for being environmentally friendly. However, there are some cons, too. The presence of water and free fatty acids in the biodiesel makes it more corrosive than petrol-diesel, and this is an undesired feature. Corrosion induced by contact with biodiesel both reduces the life of metal parts and deteriorates the fuel properties, hence adversely affects engine performance. Therefore, the corrosive characteristics of biodiesel are very important for long term durability of engine components. In this study, we tried to investigate the corrosive effects of biodiesel and blends on engine parts by evaluating and comparing test results from earlier studies for different periods at different temperatures with different biodiesel fuels. Remedial measures to inhibit or mitigate corrosive effects of biodiesel by using additives are also tackled.